my intention is not to hog this site, i have questions i hope will be pf interest to others. a ways back inbreeding was discussed in exhibition fowl. my question is, to gain and maintain a high rate of lay in egg production strains and a high rate of gain in meat production birds, wouldnt yhere have to be a good deal of linebreeding and some closer inbreeding.
Industry does worry about inbreeding, but they have large enough populations and put selection pressure to counter inbreeding effects. They also maintain a pedigree and do not breed close relatives.
Robbpa...you would be interested in knowing W.C.
i have recently called the library and requested several books on these subjects. the only book i have in my personal library is ANIMAL BREEDING ,l.m. winters. a leftover from my fathers days @ penn state u. i will begin with it . you all have been very helpful here . it is appreciated.
You can select against inbreeding effects, but most backyard breeders can't do it because they never make enough matings to do any worthwhile selection. It ends up to be a matter of luck if you select the right matings to carry on your lines.
Rokimoto, I "agonized" for several weeks about
In school I learned that there were two aproaches to science; Pure and Applied. I hated pure science because it was nothing but memorizing laws. What I really enjoyed was applied science; how those laws affect life. I believe the truly intelligent are the ones who can take the laws of genetics and apply them to breeding and help others do likewise. Is there anyone around here like that?
japman did you just now arrive? i have read several here who have gone to the trouble to answer questions for people who said," i have a dumb question, but ". you could say they only want to display superior intelligence, or training, etc.,but, we dont know who they are so what would be their point. i think, this subject just plain is of interest to them. we all like to talk of what we know. at first i took offense at infomaniacs latest comments, but i was wrong. i believe he is 99.9% correct. whats you story man.
IMHO Info is basically correct. But the problem is more than likely, (in my case anyway) the general readership is ignorant of genetics.
You have to get lucky to start a population with one male and two females and get it to reproduce adequately after about three generations. Half the genes of the first generation of progeny come from only one bird (the male). If the male carries too many detrimental genes you can bet that you will have problems. If you get lucky the male will have fewer detrimental genes than expected.
I really only have one problem with the dialog on this subject. It is with the statement made by Infomaniac ,"I am not criticising anyone here ... I just don't believe that 99.99% of the people in the fancy care about breeding genetics or coefficients of
Well.... Japman... you are welcome to your opinion
You are right. We both have the freedom to our opinions. But, you don't have a very good commentary on the Americans who provide you with this freedom.
Well, here we go again. Info, I must agree with you. The average (emphasis on the average) American is not near as bright as they could be. If every American child even bothered to learn what is taught in school they would be doing better than most.
I agree (and sort of disagree) with these posts. You can count me in as one of the people who don't know much about genetics and all the mumble jumble amout ribonucleic acid and gene strands and stuff. And yes, I think most people would rather be told what to do instead of learn about it from experience.
would this be correct then, AvgAm CItzn X avgamcitzn would produce 25% not willing to learn, 50% just dont give a damn,24% try. hopefully this can somehow leave 1% who do learn.
My apologies to the regular readers here. I am not
Robbpa, And then would this 1% be out of the less than 1%, who are interested in or are breeding poultry??? I would rather guess the percentage of exhibition/breeding birds of best quality from each hatch. That would be a more meaningful equation for me! Hoo- 000 CJR
aww, it dont mean nuthin. i am not at all politically correct myself, dont particularly care for those that are. i am alo partially disabled. this allows more time to devote to a poultry breeding program. it also allows time to research breeds and genetics. i have touched on breeding programs with beagles and was quite successful at it. had to quit, cant see the dogs at more than 30 feet. something i have noticed, many people keep a great variety of birds. now, how dothey run a management program?? i am hoping to run but 2 varieties of 1 breed and it seems that will keep me on my toes. the reason i come here is to learn, and i have. i believe one thing i learned is there is a huge difference between those who keep chickens and chicken breeders.
Info, quit apologizing for stating your opinion. Your entitled to it. I'm far from offended.
By Rokimoto on Monday, December 24, 2001 - 12:55 am:
The egg industry did some inbreeding at the beginning, starting lines from single superior layers, some commercial lines still do have a very high inbreeding coefficient, but the lines do not need optimum reproductive capacity because the commercial layers are often a 4 way cross. You can cross 4 different lines that do not have commercial production capability, but the hybrids have hybrid vigor.
You cross two lines and you get hybrid vigor and hybrid hens that will lay more eggs than either parent so that you can cross these to another hybrid (two different lines) to produce the final commercial chicks that will still have hybrid vigor and produce eggs like bandits.
By Infomaniac on Monday, December 24, 2001 - 02:26 am:
Carefoot's comments about inbreeding in
Crawford's volume... There are also chapters
there devoted to the development of meat and layer
lines... Carefoot points out that inbreeding is not
always bad and negative effects can be selected
against.
It's not simple to develop a layer line or a meat line
and an intelligent strategy is needed. A lot of
experimentation and data collection and record
keeping and analysis is required.....I don't want to
be a nay-sayer.... but it is worthwhile to take a look
at how these things are done by the pros.... You
will find that in the Crawford book.
Good luck!
By Robbpa on Monday, December 24, 2001 - 02:18 pm:
By Rokimoto on Wednesday, December 26, 2001 - 11:33 am:
If you look at the chicken literature you will find that when inbred lines were created they used full-sib matings. 80 to 90% of these lines failed to go past around 5 full-sib matings (failed to produce one fertile son and daughter to carry on the line). If you were lucky and started with the winners you could make it, but you are going to fail most of the time if you are only making 2 or 3 matings for each of your lines.
Full-sib mating is the most intense inbreeding that you could do. One of the ideas for why these lines fail is that there are recessive detrimental mutations that everyone has. Many of these mutations are not recessive lethals, but just reduce the viability of the animal a little. The problem is that if you accumulate too many of these detrimental mutations you fall below a certain threshold and do not reproduce very well. Since these detrimentals are not lethal you can fix them in your lines by chance. Fixation is when all the animals have two copies of the mutations. The fastest way for chance fixation to occur is by inbreeding. If you try not to mate close relatives you make it less likely that you will accidently fix these detrimentals in your line, and you may be able to give yourself enough breathing room to select against the worst effects.
The benefits of inbreeding are that when you do not know what you are selecting for if you inbreed superior animals you are more likely to fix the desired genes by chance in your population, but you will also run the risk of fixing the detrimental genes.
There are methods that people have used to beat this problem. Chicken have a genetic load of about 6 and we can make some inbred lines, but quail have a genetic load of about 8 and 100% of the full-sib lines fail by the 4th generation full-sib mating. No full-sib mating has worked once the progeny exceed F=0.375. One study exceeded this limit by cousin matings, and another succeeded in going to F=0.5 by selection and making as many full-sib matings as they could from the surviving families. Eventually the few surviving lines had hundreds of matings going. Most backyard breeders do not have enough mating pens to do this. The problem is that when you do selection like this your birds are probably not as inbred as you think. F is a measure of homozygousity by descent (both members of a pair of genes come from the same ancestor). In theory the quail lines had an F=0.5, but since there was very intense selection there was probably selection for a lower F value animals in each generation. This just means that the heterozygotes were selected for. So selection may have decreased the rate of effective inbreeding.
This was demonstrated in one maize study where the researchers compared the estimated F value of their lines to the real F value by analyzing the sequence of the genes. They found that when their lines were supposed to be over 90% inbred (F=.90) that they were only F=0.75 and some even lower. They tried to minimize selection by planting a row of plants for each line and selfing them (crossing the pollen to the ears of the same plant), but if the first plant in the row didn't produce enough seeds to plant next year they went to the second plant in the row, and on down the line. So even though they tried not to select they were sort of forced to do some minimal selection, and there was probably some natural selection in seeds that did not germinate etc.
Backyard breeders inbreed all of the time. You don't usually get monsters, but the viability of your line does tend to decrease. You can combat this with selection, but you have to make enough matings so that you can see which ones are doing the best and not breed from the ones that aren't. Most backyard breeders will just get more birds when their lines begin to fail, so it isn't a big deal and line breeding (mating the superior parent to its offspring) is one of the fastest ways to set the color or body type in your line, but you run the risk of fixing the detrimentals that you can't see in the line too. You can think of the detrimentals as rumpless, but you can't see them. You know that when you have rumpless the reproductive capacity of your line is decreased, there are a lot of defects that will decrease the reproductive capacity of your birds that you can't see in outward phenotype, but if you fix them in your line by inbreeding you will not be able to get rid of them unless you bring in new blood and make outcrosses.
By Infomaniac on Wednesday, December 26, 2001 - 06:18 pm:
trying to explain inbreeding on this board. Finally,
after some time.... I felt that most readers
would not appreciate the concept of the
coefficiencient of inbreeding, F. Next year, (my plan
is to) release a poultry program that evaluates the
coefficient of inbreeding ( and many other genetic
things) given specific genetic information.
I am not criticising anyone here ... I just don't
believe that 99.99% of the people in the fancy care
about breeding genetics or coefficients of
inbreeding or anything else that is genetic... they
just want someone to TELL them what they're
gonna get if they breed bird X with bird Y. I
apologize for my negative opinion of the
motivations of the people in the fancy.. but, frankly,
this is my honest opinion... 99.99% of the fanciers
really don't give a darn about genetics... they would
just like someone who DOES know about genetics
to TELL them what they 're gonna get when they
breed Bird X with Bird Y.
By Japman117201 on Wednesday, December 26, 2001 - 07:08 pm:
Japman
By Robbpa on Wednesday, December 26, 2001 - 08:23 pm:
By HannahH on Wednesday, December 26, 2001 - 09:31 pm:
Most of us have our backyard flocks (or several of them!) and would like to raise a few nice birds. I lucked out and got some nice Sultans (I have 3 total now) that I'd love to breed.
After reading the posts here, it sounds like you need alot of birds to get good results.
I started with 6 hatchery chicks, and now have 32 birds total. Of 32, 10 are standard, 11 are bantam, 8 are chicks (bantam), and 3 guineas.
I've been reading these genetics postings to try to make sense of it all, and still feel pretty lost. Guess I'm going to have to get a new library card and do some reading. But most of us don't really have the time to do all the "homework" that's necessary to understand all of this.
I did like Info's comment about people thinking they understand something when it no longer bothers them. I agree, and have probably been guilty of such.
However, to Rokimoto and Info, I totally appreciate you taking the time to discuss these issues. It's obvious your both well educated and willing to share that education.
I thank you for taking the time to be so helpful to us time deprived (and genetics information deficient) folks out here!!!
By Rokimoto on Wednesday, December 26, 2001 - 11:28 pm:
You can limit the inbreeding by keeping a pedigree and breeding the male progeny of the first generation back to the unrelated female parent. This will maximize the genetic diversity of your population and may help you keep your line going.
I wouldn't worry about inbreeding if your birds are mongrel stock and you are just mixing and matching. You can always go back to the hatchery and get more birds. All you have to do is add a few new cockerals every once in a while and your fertility should be normal.
By Japman117201 on Thursday, December 27, 2001 - 04:55 pm:
inbreeding or anything else that is genetic... they
just want someone to TELL them what they're
gonna get if they breed bird X with bird Y."
I believe that this is a condescending and inaccurate evaluation of the poultry fancy that I am familiar with. The poultry fancy that I am familiar with is made up of some of the top breeders in this country. Many of which would be bored stiff with this dialog, but allow them to pick two pairs of birds from your yard and give them five years of selective line breeding, and they will beat anyone hands down. Sorry that I used a 2X4 to get your attention.
By Infomaniac on Thursday, December 27, 2001 - 06:57 pm:
and you have a right to it. And I also have a right to
my opinion.
I spent more than a year setting up a poultry
genetics website and trying to build a readership /
clientel. Many poultry people told me that I was
wasting my time ... that most of the fancy just want
someone else to answer their questions... they
don't want to actually understand anything, rather
they want to have access to others who do
understand something who will have the patience
to answer their questions.
I will not pander to or glorify the masses (as
politicians do)....frankly, the average American is
not at all knowledgable about much of anything.
The average foreigner (European, Asian,
Russian...) is much more knowledgable than are
Americans. But, I was not necessarily talking to
you or anyone else that participates in this board
specifically. I was simply expressing my opinion
that I have formed based on my past experiences.
I meant no offense by my comment. My comment
is my honest opinion. If you are offended.... I
respectfully say "that is your problem" . you are
responsible for how you percieve your
environment. The way you choose to percieve your
world has nothing to do with me or my opinoins. If
the shoe I described didn't fit you, then you
shouldn't have tried to wear it.
I have a right to my opinion too. It really is a free
country (the free-est county I know of) and I invite
you to ignore my posts! No one makes you read
what I write.
By Japman117201 on Thursday, December 27, 2001 - 07:29 pm:
By HannahH on Thursday, December 27, 2001 - 09:02 pm:
School is the last thing most kids really care about. They're more interested in video games or other couch potato pastimes.
I pretty much breezed through high school, and can't understand to this day how kids graduate when they can't read! I blame the parents and yes, the school systems themselves.
Then again, when I was in school, I didn't have to worry that the guy sitting next to me was packing an Uzi, either. Oh well.
Japman, I see where your coming from also. If you've just started reading Infomaniacs posts, you will find Info is one-of-a-kind, but seems to be good hearted and willing to share poultry experience.
And that's a good thing. So just relax, and enjoy the Coop, I know I sure do!!
By Josh on Friday, December 28, 2001 - 12:37 am:
However, I don't think it is right to say that nearly 99.999-whatever percent of people are dull and would like to be "ordered" and told what to do. It depends on your perspective and your personal experience. If you've only had contact with a bunch of people who aren't intelligent (or dont use what intelligence they do have), then of course you would say that nearly all of chicken fanciers are dull. But if you come from a forum or group where nearly everyone is like CJR and Dr. Rokimoto, then that statement would be wrong.
I sort of agree that Americans are laid back couch-potato folks who would rather be given options than make options themselves. There are exceptions, but I think overall most Americans are...not making full use of their God given talent. In Hawaii, the public schools scored the LOWEST of all states, and man was it low! I think the reason for this is because the schools give a hundred children only one teacher who sometimes doesn't even care about the children.
Like HannahH, I enjoy The Coop immensely. Thankfully, everyone in the coop are not one of the 99.9999% of fanciers who don't know anything. The world is gifted to have "exceptions" like Coop visitors.
By Robbpa on Friday, December 28, 2001 - 04:04 pm:
By Infomaniac on Friday, December 28, 2001 - 04:33 pm:
reading this thread for obvious reasons.... I don't
want to start another political thread.
I did read Rob's post and I just want to say again
that I NEVER intend to offend anyone. I am
sometimes blunt, a-political, non-PC and so on...
(and Rob, I am not male). I am constantly thankful
that we live in a free society ... had I lived in Russia
under Stalin, or in China under Mao, or in Iran or
Iraq or almost any fundamentalist Islamic
country... I would have been killed. I know this with
certainty...
I express in this post that I do NOT intend to be
offensive to anyone. I really don't want to offend
Rob or CJR or Hannah or Rokimoto... I feel
fortunate to live in America ... where I can have
opinions that you don't agree with and no one
comes to imprison me or execute me... I am very
serious... I feel so much intensity for the women of
Afganistan... intelligent people who have been
oppressed from the beginning of time...
What a luxury we have in our freedom! most of the
world doesn't have this... don't even think about the
material wealth we have.... most of the world
doesn't have the luxury of saying what they think.
By Cjeanr on Friday, December 28, 2001 - 04:35 pm:
By Robbpa on Friday, December 28, 2001 - 08:42 pm:
By HannahH on Saturday, December 29, 2001 - 12:45 am:
Josh, CJR and Rokimoto are exceptions to the rule. And so are you.
Robbpa, I'm not always politically correct either, (far from it) but like Info, I can speak my mind and not be persecuted for it. Thank God for America, and the freedoms we have here. (I consider myself part of your 25% who try, and hopefully will one day be in the elite 1%!) ;^}
You are all fantastic!! And Happy New Year!!